In a dry pan over low heat, roast the whole peppercorns for 15 minutes until fragrant. Let cool completely and grind to a fine powder.
In the same dry pan, roast the salt until it turns slightly yellowish. Let cool and mix with the ground pepper powder.
Pat the shrimp completely dry with paper towels and coat evenly with potato starch or cornstarch.
Heat oil in a large pan until hot. Fry the coated shrimp until golden, crispy, and cooked through, about 3-4 minutes per side.
Add the chopped garlic, sliced hot pepper, and salt-pepper mixture to the pan. Toss everything together for 30 seconds until fragrant.
Serve immediately while hot and crispy.